1. Field of the Invention
The present invention generally relates to a MEMS package, and more particularly to a MEMS package including a first board, a second board and a third board formed by the manufacturing process of the PCB.
2. Description of the Related Art
Micro-electro-mechanical-system (MEMS) components are gradually applied to many electronic circuits and a variety of micro sensors. For example, the MEMS components can be electro-mechanical motors, radio frequency (RF) switches, pressure transducers and accelerometers.
Referring to FIG. 1, it depicts a conventional microphone-type MEMS package 10. The package 10 includes a silicon substrate 12, an annular supporting wall 14, a capacitor 16, an operation element 18 and a cap 20. A cavity 22 is formed by the annular supporting wall 14 and the silicon substrate 12. The capacitor 16 and the operation element 18 are mounted on the silicon substrate 12 and located in the cavity 22. The cap 20 is mounted on the annular supporting wall 14 and covers the cavity 22. The cap 20 includes a through hole 24 for conveying external sound into the package. The capacitor 16 is a MEMS component and corresponding to the through hole 24, whereby the capacitor 16 is adapted to be driven by sound so as to receive a vibration signal. The operation element 18 converts a non-electric signal to an electric signal. The capacitor 16 is constituted by two metallic thin films (not shown) and a dielectric layer (not shown) located between the two metallic thin films, and thus it is necessary that the capacitor 16 is formed on the silicon substrate 12 by a plurality of photo-mask, photolithography and etching processes. However, the manufacture cost is high because the package is formed by the above-mentioned photo-mask, photolithography and etching processes.
Accordingly, there exists a need for a MEMS package and a method for manufacturing the same, being capable of solving the above-mentioned problems.